Yarn changing means for circular knitting machines



March 5,1935. 'W, MEAQER 1,993,525

'YARN cmmeme MEANS FQR CIRCULARKNITTING MACHINES Filed A i-i1 1.3, 1933 4 Sheets-Shet 1 March 5, 1935. w. A.- READER 1,993,525

YARu CHANGING MEANS on OIRCULAR'KNITTING MACHINES Filed April 13, 1935 4 Sheets-Sheet 2.

a 60 55 29 J3 45 $7 54 J1 J2 fhyflZ 4 I INVEN T0}? March 5, 1935. w. A. READER 1,993,525

' YARN CHANGING MEANS FOR CIRCULAR KNITTING MACHINES 7 Filed April 13, 1933 v 4 Shets-Sheet '3 March 5, 1935. 2w. A. READER 1,993,525

YARN CHANGING MEANS FOR CIRCULAR KNITTING MACHINES Filed April 13, 1933' 4 Sheets-Sheet 4 Patented Mar. 5, 1935 YARN CHANGING MEANS FOR CIRCULAR KNITTING MACHINES William Arthur Reader, Leicester, England Application April 13, weasel-m1 No. 666,030

In Great Britain May 2, 1932 5 Claims. (Cl. 66-440) This invention relates to yarn-changing means for circular knitting machines, and concerns mechanism of the kind wherein a plurality of mcvableyarn-feeding members are actuated by pre-arranged pattern mechanism for changing the yarns supplied to the needles of the machine, and means are furnished for trapping and severing the yarns.

The present invention comprises improved.

yarn-changing means of the above mentioned kind as will be hereinafter described.

To enable the invention to be clearly and readily understood I will describe, with reference to the accompanying drawings, a practical example thereof.

In the drawings,

Figure 1 is an elevation of a circular rib knitting machine of the cylinderand dial type to-Which is applied yarn-changing mechanism constituting-said example, and means for operating the same, the operating mechanism being partly in section.

Figure 2 is a plan view of the yarn-changing mechanism and means for operating same.

Figure 3 is a side elevation of the yarn-changing mechanism, shown in relation to the cylinder and dial of the machine.

Figure 4 is a detail side view of part of the mechanism with the positions of the two yarn guides seen'in Figure 3 reversed, and the appropriate trapper moved forward to trap the withdrawn yarn.

Figure 5 is a side elevation of part of the yarnchanging mechanism as viewed from the side opposite to that shown in Figure 3. I

Figure 6 is a sectional plan taken on line VI-VI of Figure 3.

Figure 7 is a view similar to Figure 6 but with the positions of two of the yarn guides reversed,

and the appropriate trapper device moved forward preparatory to trapping the withdrawn yarn.

Figure 8 is a view similar to Figure 7 but with the said trapper device trapping the withdrawn yarn, and a scissor device moved across to sever the trapped yarn.

Figures 1 and 2 are drawn to a smaller scale than Figures 3 to 5, and the latter aredrawn to a smaller scale than Figures 6 to 8.

Referring to Figure 1, the machine includes a stationary needle cylinder a, a stationary needle dial b, a rotary cam box 0, a rotary dial cam cap it, a framework 6, f, and supporting legs g. The upper part 1 of the framework carries rotatably a carrier h on which the yarn packages 7' for the supply of yarns 7c are mounted. The various parts aforesaid are all of usualconstruction and arrangement and therefore do not require description in detail.

Referring to the several figures oi the drawings, the yarn-changing mechanism includes piv-' oted guides 1 disposed so that their yarn feeding ends 1a move up and down on'the outside of the circle of the cylinder needles 2, i. e. down to the feeding position, and up to the non-feeding position, as shown in Figures 1 and 3. The guides are arranged side by side to turn upon a horizontal pin 3 fixed in a bracket 4 attached at 5 to the cam box 0, and for moving them as desired there is a drum 6 rotatable upon a horizontal axle 7 in the bracket and carrying removablescrews 8, prearranged for action upon heel portions 1b of the guides when the drum 6. is intermittently rotated, according to the yarn changes required. When a screw 8 makes contact with a heelportion of a guide the latter is turned to carry its feed end down from the inoperative to the operative position. The guides 1- are independently operable in the manner de-. scribed and each is controlledby a spring 9 which returns it to the inoperative position when the screw passes from under the heel portion 1b.

The screws 8 are removable and interchangeable for pre-arrangement in appropriate positions on the drum 6., The drum may for instance have series of holes in it, one series for each yarn guide, for reception of the screws 8.

Arranged above the guides 1 is a corresponding seriesof trapper levers 10 and for-operating these there is another drum 11 mounted to rotate on an axle 12 in the bracket 4. This drum also has removable and interchangeable screws 13 for acting upon heel portions 10a of the levers 10. These levers are arranged side by side to turn independently upon a horizontal pin 14 fixedin the bracket 4 and each lever is controlled by a spring 15. The. levers 10 are turned one way by the screws 13 and the other wayby the springs 15. Trapper devices 16 are attached to the lower ends ofthe levers 10 so as to be swung to and fro across the circle of the cylinder needles (compare Figures 3 and 4). The levers 10 are arranged so that when moved by the screws 13 to the yarn taking position as shown at A in Figure 4, they will assume a substantially vertical position dependent from the pivot 14, and when moved by the springs 15 to the position where the yarn a is withdrawn and held they will assume an inclined position as shownat B in Figure4.

As clearly shown in Figures 6 to 8, each of the trapper devices 16 consists of apair of spring blades which normally press together by reason of their inherent spring. These blades are attached to the lever by screws 18, so as to project at right angles from the lever in a direction towards the corresponding yarn guide. At the outer end of the trapper device the spring blades are bent outwards away from each other to form a V-shaped opening 17- for guiding the yarn between the blades. Each of the blades has on its upper edge an upstanding shoulder 19 and the front ends of these shoulders are outwardly bent similarly to the front ends of the blades, so as to produce a V-shaped entrance 20 between the shoulders. The purpose of the shoulders will be hereinafter described.

Positioned between the trapper devices and the yarn guides is a horizontal rockshaft 21 mounted in the bracket and in an arm 21a,- rigidly attached to the pin 14 and having projecting from its underside a series of pins 22, see Figures 6 to 8, there being one pin for each trapper device. These pins are each so positioned that as the corresponding trapper device swings towards the yarn to take it, the shoulders 19' of the trapper device will pass into contact with the pin.

which latter acts as an abutment. The pin is received in the V-shaped opening '20 between the shoulders 19 and consequently acts on the same to separate the spring blades 14 so that the trapper device approaches the corresponding yarn in an open condition, (see the lowest trapper in Figure 7) in order to receive the said yarn between its blades. Further movement of the trapper lever to the yarn receiving position A, Figure 4, carries the shoulders 19 beyond the abutment pin, thereby allowing the blades to spring together again and clamp the yarn, as shown in.

Figure 8. The yarn having thus been clamped between the said blades, the trapper lever then swings inwards across the needle circle carrying the trapped yarn with it, to the yarn holding position B (Figure 4). When during this movement the shoulders 19 of the trapper device make contact with the abutment pin, the rockshaft 21 turns, thereby allowing the said pin to yield and allow the shoulders to pass Without opening the trapper. The trapper thus retains the yarn. The rockshaft 21 has a limited rotary motion. As shown in Figure 5 a stop 23 is provided on the bracket 4 to prevent the rockshaft from turning beyond a certain point in one direction, and said rockshaft is controlled by a spring 24 which allows it to turn in the other direction, indicated by the arrow, and turns it back again to the stop 23 after such rotative yielding.

Referring to Figure 3, when a yarn guide 1 is in the inoperative position C the corresponding trapper occupies the position B within the circle of the cylinder needles; thus each yarn is stretched across above the circle of needles between the yarn guides 1 and trappers 16 as shown at D. When a guide is moved down to the operative position E, it carries its yarn down to the. needles 2 at the feeding position as shown at F while the end of the said yarn remains clamped by the corresponding trapper, the said yarn being.

subsequently pulled from the trapper, after being taken by the needles. Referring to Figure 4, when a guide moves from the feeding position E' to thenon-feeding position C, it carries its yarn up and the corresponding trapper swings'outwards towards and, as shown at A, engages the length G of yarn extending between the needles and the tip of the raised guide.

As will be observed the yarn-changing mechanism is arranged so that the guides 1 and the trappers work in a vertical plane. It is therefore preferable to provide a yarn positioning device in order definitely to position the yarn to be taken and held by a trapper also in a corresponding vertical plane. As shown in Figures 3, 4 and 6, there is provided a device consisting of a series of wires 25 each attached by a screw 26 to a carrier block 2'7 secured to the bracket 4 by a screw 28 so that the wires extend in the same direction as the guides alternately therewith as shown in Figure 6. The ends of the wires are connected by a bar 29 whereby they are held rigid. As shown in Figure 3, the wiresextend upwards and forwards over the cylinder needles. Thus as a guide moves to the non-feeding position C it draws the yarn extending between its tip and the last needle to take such yarn round the adjacent wire so that the length G between the wire and the higher tip of the guide is positioned in substantially the same vertical plane as the corresponding trapper so as to be taken thereby as represented inv Figure 4.

Thetrapping action occurs after-a guide has moved to the inoperative position and consequently while such guide is stationary, the prearrangement of the screws 8 and 13 in the drums 5 and 11 respectively being such that the movements of the guide withdrawn and the correspending trapper take place one after the other. After the yarn has been taken by the trapper it is severed at a point'between the trapper and the needles whereupon the trapper returns to its normal yarn holding position i. e. the relative positions of the guide and trapper are as shown at C and B in Figure 3.

For severing the yarn there is provided a severing device which is common to all the trappers and yarn guides, and consists of a pair of scissor blades carried by a lever mounted to move in' a horizontal plane so as to carry the scissors into and out of position for severing the yarns. The scissors are positioned on the lever so that when swung into position they will act upon any yarn which happens to be stretched between the needles and a raised finger.

The scissor device comprises a blade 30 fixed on a carrier lever 31 and a blade 32 pivoted thereon at 33. The pivoted blade is controlled by a spring 34 and has a projecting foot 35. In the inoperative position (Figures 2 and 6) the blades are normally held open by the spring and another spring 36 normally holds the device in said inoperative position i. e. away from the trappers and guides. The carrier lever is turned, whenever a yarn is to be severed, so as to carry the scissors into a position shown in dot and dash lines in Figure 7 where its open blades take the yarn between them and during such movement of the said lever the foot makes contact with a fixed stop 37 on the bracket 4 thereby causing the movable blade to turn on its pivot and cut the yarn, as represented in Figure 8. After this the lever swings away again and the spring opens the scissors.

The yarn-changing mechanism is attached to the cam box 0 so as to revolve therewith, and the drums 6, 11 and carrier lever 31 are actuated by means which make contact with cams movable into and out of the circular path of said means by pattern mechanism. For intermittently rotating the drum device 6, there is provided a ratchet wheel 38 on the drum, a controlled slide 39 on the base of the bracket 4 and a clawker 40 on the slide to drive the ratchet wheel. The slide 39 a block 6'7 carried by the framework 6.

is fitted with. a roller 41. A cam 42 movable into the circular path of the roller moves the slide against the influence of aspring 43'and racks the drum round. Forwintermittently rotating the. drum 11 a slide 44 is slidably'mounted on the bracket 4 and is fitted with a roller 45 to engage a cam 46 movable into and out of its circular path. The slide is connected to a pawl 4'7 by means of a nut and bolt connection 48 the bolt of which extends through a slot 49 in the bracket 4. The slide is controlled by a spring 50; The pawl 47 engages a ratchet wheel 51 fast on the drum 11, and there is a pin 52 fixed in the slide which works in a slot 53 in the bracket 4 to limit the movement of the slideunder the action of the spring 50. When the slide 44, is moved by the passage of its roller 45 in contact with the cam v 46 the drum is racked'round.

The carrier lever 31 is pivoted at 54. on a block 55 attached to the bracket 4. The lever is moved in one direction by a spring 36 and in the other by means of a slide 57 whichmoves in the block 55, and a pin 58 which is fixed in the slide and works in a slot 59 in the carrier lever. The slide 57 is fitted with a-roller 60, and a cam 61, movable into 7 and out of the circular path of the roller, is procam the pin 58 acts to turn the carrier lever 31 upon its pivot for the purpose already. described. The cams 42, 46 and 61 are mounted on the framework e and are-moved upgand down i. e. into and out of operation as desired by means consisting of a drum 62 having thereon a pattern chain 63, which has elements such as 64 thereon for acting upon a slide 65, controlled by a spring 66, and movableradially in a horizontal plane in One end of said slide is shaped as at 68 for contact with a similarly shaped end 69 of a slide '70 vertically slidable in a block 71 on the block 67. Said rod carries the cam 42 which has fixed to the underside thereof guide rods '72 attached thereto by nuts '73. These guide rods '78 slide in the aforementioned block '71. The cam 61 is mounted on the cam 42 by means of rods 74 and nuts '75. The cam 46 is mounted on the cam 61 by rods '76 and nuts '77. To put cams 42, 46 and 61 into the operative position, an element 64 forces the inclined face 68 of the slide against the inclined face 69 of the slide '70. Thus the slide '70 is forced upward carrying the aforesaid cams with it. The slide 65 is returned to the inoperative position under the influence of the spring 66, when released, and the cams 42, 46 and 61 fall to the inoperative position by gravity.

The yarn guides 1 when in the operative positions have their feeding ends 1a disposed in the angle formed by the cylinder needles (2) and dial needles '78 which are moved respectively up and out to clear. The guides move upwards from this position to the inoperative position. When a yarn change occurs the selected yarn guide moves down to the feeding position and the raised cylinder needles draw the yarn over projected dial needles while the end of the yarn is held by the associated trapper device. The dial needle recedes and takes the yarn in, and

the end of the yarn is pulled out of the trapperdevice. When the yarns are withdrawn from knitting the trappers take the clamped ends of yarn to a position over the dial and within the extended circular line of the circle of the cylinder needles as already described herein. In the case of a plain machine i. e. without a dial, the trappers hold the yarns within: the extended circular line of the cylinder needles and at a suitable level above said needles. The described disposition of the trappers in relation to the needles and'to the yarn guides constitutes an important feature of this invention. .The effect of the said arrangement is that when a yarn guide is dropped from the non-feeding to the feeding position it lays its yarn between two adjacent cylinder needles thus ensuring that the yarn will be taken by said needles. If there are no dial needles, the yarn thus laid is drawn across thecylinder needles by the relative motion of the-guide and needles. In a rib machine the yarn laid betweenthecylinder needles is drawn across the. cylinder needles in the same way and is pulled by these needles across the intermediate projected dial needleor needles. The yarn is thus positively taken by the needles at each yarn change.

As usual the yarnguides are actuated so that when changing-the yarns, the yarn being knitted is not withdrawn until the new yarn has been covered or taken by one, two or more needles.

When withdrawing a. yarn the guide moves from the feeding to the non-feeding position i. e. the raised position and, as already described, the corresponding trapper swings forward and clamps the yarn. The trapper remains stationary after clamping the yarn while the severing device advances and severs the yarn after which the trapper swings inwards to the described position within the extended circular line of the cylinder needles.

The improved yarn-changing mechanism may be used for changing the knitting yarn or for changing yarns which are fed in addition to one or more knitting yarns. v

What I claim'then is: 2

1. In a circular knitting machine, yarn-changing mechanism comprising pivoted yarn guides, a device consisting of a drum having elements prearranged thereon for actuating the yarn guides,

means for rotating the drum intermittently,-piv otedyarn' trapperscorresponding'with the yarn guides and movable. independently thereof to yarn taking and holding positions, a device consisting of a drum having elements prearranged thereon for operating the trappers independently of but in timed relation with the yarn guides, said trappers including elements which are normally spring pressed together, a pivoted device adapted to open the trappers and to allow same to close again upon movement to yarn taking position but capable of yielding upon reverse movement of the trappers so as not to open them, a device for locating awithdrawn yarn in a definite position in relation to the corresponding trapper for engagement thereby, means for intermittent- 1y rotating the trapper operating drum, a yarn severing device common to all of the yarn guides and trappers. and means for operating said de- 7 vice.

2. Yarn-changing mechanism for a circular knitting machine comprising pivoted yarn guides, springs and a drum having elements prearranged thereon for moving the guides to inoperative and operative positions, means for operating the drum, a plurality of pivoted trappers movable independently of the guides to yarn taking and holding positions, said trappers including elements normally spring pressed together and having shoulders thereon, springs and a drum having elements prearranged thereon for moving the trappers to the yarn holding and yarn taking positions, means for operating the drum, a pivoted device including pins corresponding with the trappers and adapted to. act upon the shouldered elements to open the trappers and to allow same to close again upon movement to the yarn taking position, but capable of yielding upon reverse movement of the trappers so as not to open them, a device for locating a withdrawn yarn in a definite position in relation to the corresponding trapper for engagement therebyj, a yarn severing device of the scissor type common to all of the yarn-feeding members and the trappers, and means for operating said device to sever a yarn after withdrawal from the feeding position and while the corresponding trapper is stationary in the yarn taking position.

3. In a circular knitting machine, yarn-changing mechanism, comprising a plurality of independently movable yarn-feeding members, prearranged pattern mechanism for actuating said members selectively, a corresponding plurality of trappers, each constituted by cO-operating yarn holding elements and completely movable independently of the others to yarn taking and holding positions, means capable of prearrangement for selectively moving the trapping devices independently of but so as to correspond with the selective operation of the yam-feeding members, said yarn-feeding members and trappers being arranged to move in corresponding vertical planes, yarn positioning means whereby when a yarn is withdrawn from feeding position a length thereof is positioned in the plane of the corre-- sponding trapper for engagement of the trapper, and means for severing the yarn.

4. In a circular knitting machine, a needle cylinder, independent needles in said cylinder, yarn-changing mechanism comprising a plurality of independently movable yarn-feeding members, prearranged pattern. mechanism for actuating said members selectively, a corresponding plurality of yarn trappers, each constituted by co-operating yarn holding elements and completely movable independently of the others to yarn taking and holding positions, means capable of prearrangement for controlling and moving the trappers independently of but so as-to correspond with the selective operation of the yarn-feeding members, said yarnfeeding members and trappers being arranged to operate in vertical planes, yarn positioning means whereby'when a yarn is withdrawn from feeding position a length thereof is positioned in the plane of the corresponding trapper for engagement by the trapper, means adapted to open the trappers upon movement thereof to yarntaking position but to have no action on the trappers so that they remain closed on return movement, said trappers being disposed in such relation to the feeding members that when the yarns are withdrawn from knitting the trappers take the clamped ends of the yarns to a position above and within the extended line of the circle of needles, and means for severing the yarns.

5. In a circularv knitting machine, a needle cylinder, independent needles in said cylinder, a series of yarn feeding members each movable to an operative feeding position and an inoperative, nonfeeding position in a vertical plane on the outside of the needle cylinder, means for operating said members according to the order in which they are to be brought into and out of operation, a plurality of yarn trapping devices each cornprising co-operating yarn holding elements and completely movable independently'of the other devices over the needle circle to yarn taking and holding positions in the same vertical plane as the corresponding yarn feeding member, the action being such that each device when operated moves outwards over the needle 'circle to take the corresponding yarn and then inwards, carrying the trapped yarn with it to a position on the inside of the extended line of the needle circle, means capable of prearrangement for controlling and operating the trappers independently of the yarn feeding members whereby after a yarn feeding member has been operated to withdraw its yarn and while said member is stationary the corresponding trapper is moved to take and hold the yarn and means for severing the yarn.

WILLIAM ARTHUR READER. 

